This invention relates generally to thermal protective devices for recessed lighting fixtures and more particularly, it relates to an arrangement for mounting a thermal protective device in a spring loaded manner on the outer surface of the housing wall of a recessed lighting fixture.
In the lighting industry, it has been encountered heretofore that recessed lighting fixtures which are mounted in a ceiling surface may become unsafe and overheat at times when lamps larger than the required or recommended wattage are used in the lighting fixture, or when the fixtures are covered with insulating material. This has been known to cause fires where the excess heat generated is not effectively dissipated. In view of this existing condition, safety organizations, such as National Fire Protection Association, and Underwriters Laboratory, have set up requirements for using some type of thermal protective device in lighting fixtures which will automatically shut off the lamp when a predetermined temperature is exceeded. Thus, there has arisen the need of mounting properly and efficiently a thermal protective device in a recessed lighting fixture which will sense accurately the temperature in the vicinity of the light fixture housing so as to prevent overheating of the lighting fixture, thereby avoiding a potential fire hazard.
In U.S. Pat. No. 4,314,223, issued to P. J. Kristofek on Feb. 2, 1982, there is disclosed a thermal protective device for interrupting a current to the lamp circuit of an electrical lighting fixture when the temperature at a preselected location in the fixture reaches a predetermined level. The protective device is comprised of a receptacle member and a plug member adapted for joining with the receptacle member. The protective device is merely suspended within the housing of the lighting fixture.
In U.S. Pat. No. 4,450,512, issued to P. J. Kristofek on May 22, 1984, there is shown an arrangement for mounting a thermal protective device in a recessed lighting fixture which includes a clip-on receptacle adapted for mounting in an aperture formed in the side wall of the housing of the lighting fixture. The receptacle is dimensioned so as to receive and retain a thermal protective device. The case is formed with a projection that defines a window area at which a bimetallic switching element is positioned. The window area is aligned with an opening in the side wall of the lighting fixture housing so as to insure accurate sensing of the temperature on the outer surface thereof.
The present invention represents an improvement over these above-mentioned patents for some types of recessed fixtures in that it includes an arrangement for mounting a thermal protective device in a spring loaded manner on the outside surface of the housing wall of the recessed fixture. The arrangement of the present invention is relatively simple in its construction and is easy to manufacture and assemble.